The invention relates to a guitar belly structure having the resonance box of an acoustic guitar, in particular.
The belly of a guitar having a resonance box, such as an acoustic guitar but including an electric guitar, is ordinarily produced by preparing the reverse plate or rear plate and the side plates of the guitar belly using naturally dried wooden plates and joining the reverse and side plates together. In this kind of wooden guitar belly, however, natural drying for a long period of time is necessary in order to eliminate internal stress and strain in the natural wood. Unsatisfactory natural drying will cause the wooden plates of the guitar belly to deform due to internal stresses after the guitar has been manufactured, producing small deformations in the guitar belly, and disturbing the tension of the guitar strings. Furthermore, natural drying requires time and expense, and cost is incurred for storage of the guitar.
Preparing a guitar belly made of wood according to prior art, moreover, requires the separate manufacturing steps of preparing a reverse plate and a side plate and then gluing these plates together to form an integral body.
Recently, attempts have been made to assemble a guitar belly comprising the reverse plate and the side plates as one body using plastics reinforced by glass fiber, etc. A guitar belly made of plastic as its main ingredient avoids the need for and time spent in the natural drying process which has been required for the wooden plates, and there is no contraction due to internal stresses. Since both the reverse plate and the side plates can be formed continually as one body by means of press forming, furthermore, this avoids the manufacturing step of gluing together the reverse plate and the side plates.
In the known guitar belly whose main ingredient is plastic, however, there has been a tendency for the belly to deform over time because of the tensile force of the strings at the time when they are put to use, simply because the reverse plate and the side plates are formed integrally.